A sand gnat is a small biting fly. This insect is commonly called a "no-see-um" because it is the smallest of the biting flies and goes unnoticed until after a bite. About 60 species of sand gnats make homes in coastal areas of South Carolina, Georgia and Florida.
A sand gnat can draw blood with its minute, blade-like jaws. Some people have allergic reactions to the bites. A few species of sand gnat transmit diseases to cattle, horses, deer and sheep. Sand gnats can't fly in winds over 3.5 miles per hour, and cooler temperatures also keep these insects at bay. The gnats are often found in swarms on populated beaches.